On 10/4/23 5:18 AM, Verma, Vishal L wrote: > On Tue, 2023-10-03 at 09:34 +0530, Aneesh Kumar K V wrote: >> On 9/29/23 2:00 AM, Vishal Verma wrote: >>> Large amounts of memory managed by the kmem driver may come in via CXL, >>> and it is often desirable to have the memmap for this memory on the new >>> memory itself. >>> >>> Enroll kmem-managed memory for memmap_on_memory semantics if the dax >>> region originates via CXL. For non-CXL dax regions, retain the existing >>> default behavior of hot adding without memmap_on_memory semantics. >>> >> >> Are we not looking at doing altmap space for CXL DAX regions? Last discussion around >> this was suggesting we look at doing this via altmap reservation so that >> we get contigous space for device memory enabling us to map them >> via 1G direct mapping entries? >> > Hey Aneesh - was this on a previous posting or something - do you have > a link so I can refresh myself on what the discussion was? > > If it is enabling something in CXL similar to the --map=mem mode for > pmem + device dax, that could be incremental to this. Yes. Agree that we can do that incremental to this. https://lore.kernel.org/linux-mm/b6753402-2de9-25b2-36e9-eacd49752b19@xxxxxxxxxx -aneesh
